Emergency power supply



FIG. 1 is a side perspective view of the new design of an emergency power supply;

FIG. 2 is another side perspective view thereof;

FIG. 3 is a front elevation view thereof;

FIG. 4 is a rear elevation view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a left side view thereof;

FIG. 7 is a top view thereof; and,

FIG. 8 is a bottom view thereof.

The broken (dashed) lines show portions of the emergency power supply that form no part of the claimed design. 

CLAIM The ornamental design for an emergency power supply, as shown and described. 